Chemical Processing

Phoenix Contact and Flowserve join Endress+Hauser’s Open Integration Partner Program, which strives to mitigate risks when commissioning customer plant by ensuring that operators can easily integrate their devices and components into automation systems, according to the company. Phoenix Contact and Flowserve join eight companies already in the program: AUMA Riester, HIMA Paul Hildebrandt, Honeywell Process Solutions, Mitsubishi Electric, Pepperl+Fuchs, Rockwell Automation, R. STAHL and Schneider Electric.
Although today’s communication components (HART, PROFIBUS, FOUNDATION Fieldbus, EtherNet/IP or PROFINET) are rigorously tested, there are still countless ways in which they can be combined and there is a residual risk that minor…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Understand what achieving an effective predictive maintenance program entails

Processors have relied on gas chromatographs (GCs) since the 1950s to provide real-time compositional data to control systems. Today, tens of thousands of GCs serve in a diverse range of plants — making the GC the analytical workhorse for online…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Mettler Toledo offers SmartCal, a test substance offering a fast way to verify the performance of a moisture analyzer, according to the company. Using SmartCal, performance testing reportedly takes 10 minutes and it is done in the same easy way as a regular moisture measurement.
Additionally, as an overall functionality assessment, SmartCal simultaneously tests both the heating and weighing units, according to Mettler Toledo. When results lie within expected tolerances, it lends validity to all measurements made since the previous test. These results are viewed in a series of clear, readable measurement reports for straightforward monitoring. They can either be stored directly in the instrument or manually entered into a free, validated…

After a three-year software evaluation period, BP reportedly selects aeSolutions’ aeShield to assist asset personnel in monitoring control, alarm and safety instrumented systems (CASIS) performance for all upstream oil and gas assets. To date, it has been a challenge to automate the monitoring of these devices due to the lack of common systems in place across BP’s facilities, according to aeSolutions.
aeShield allows centralized reporting, standard enforcement consistent with internal procedures, reduced man-hours, monitored IPLs and efficient management of change (MOC) tracking, according to the company. During initial rollout, BP will reportedly focus on HAZOP/LOPA studies, safety requirements specification, SIL verification and IPL…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

A new nonmetallic catalyst promises to enable economical hydrogen-based substitution reactions that now require expensive or hazardous synthesis routes.

A new nonmetallic catalyst promises to enable economical hydrogen-based substitution reactions that now require expensive or hazardous synthesis routes, e.g., making hydrosilanes from chlorosilanes as well as hydrides from halides, believe researchers at Goethe University, Frankfurt, Germany. The borane catalyst splits hydrogen molecules under mild conditions and should suit broad-scale use, they say.
The researchers created the catalyst by introducing boron atoms into a common organic molecule (Figure 1). The catalyst provides ambiphilic metal-like reactivity toward H2; tests so far indicate yields are comparable to conventional metallic catalysts.
“What we additionally need is just an electron source. In the laboratory we chose…

A carbon-based molecular sieve membrane combined with a reverse osmosis process could significantly reduce energy needed to separate alkyl aromatics hydrocarbon molecules, says a research team from the Georgia Institute of Technology (Georgia Tech),…

Conco Systems, Pty Ltd. of Heatherbrae, Australia, an affiliate of Conco Services Corporation in Verona, PA, USA, acquires Gogolok IndustrieService GmbH (GIS) of Magdeburg, Germany. GIS specializes in industrial cleaning of plate heat exchangers, air cooled condensers and general maintenance cleaning services. The incorporation of GIS infrastructure, human resources and service capabilities into the Conco family will support Conco’s growth in the European market and an expansion of the global service portfolio, according to the company.
Conco Systems Pty Ltd. is the Australian contingent of a worldwide group of Conco companies providing condenser and heat exchanger products and services to the power generation and industrial sectors.

The U.S. Department of Energy announces nearly $25 million to enable innovative electrical motors used in manufacturing.

The U.S. Department of Energy announces nearly $25 million for 13 projects aimed at advancing energy-efficient electric motor technologies through applied research and development. The Office of Energy Efficiency and Renewable Energy’s (EERE) Next Generation Electric Machines projects will address the limitations of traditional materials and designs used in electric motor components by cost-effectively enhancing their efficiency, improving their performance and reducing weight. This effort will support approaches to improve the technology in industrial electric motors, which use approximately 70% of the electricity consumed by U.S. manufacturers and nearly a quarter of all electricity consumed nationally, according to EERE.
Improvements…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Advisory firm International eChem says that warning signs from the chemical industry point to a global recession in 2017, according to an article from Investment Week. The global chemical capacity utilization percentage (CU%), a measure which the firm says correlates closely to global GDP, reportedly dropped to its lowest level since 2009 this year, which the firm warns is an indicator of global economic slowdown.
The CU% has reportedly been in a steady decline for the last year, according to the firm’s chairman Paul Hodges. In the article, Hodges also warns of increased currency volatility due to protectionism-driven trade wars.
Read more about the firm's predictions here.

Transferring expertise and knowledge of experienced staff to engineers beginning their careers is hardly a new issue for chemicals makers. However, the ongoing wave of retiring baby boomers (see: “Retirement Casts a Long Shadow”) is prompting…

Siemens Water Solutions will use Meidensha Corporation’s ceramic flat-sheet membrane in its new PACT Membrane Bioreactor for wastewater treatment.

Siemens Water Solutions will reportedly use Meidensha Corporation’s ceramic flat-sheet membrane in its new PACT Membrane Bioreactor (MBR) for wastewater treatment in the oil refinery and petrochemical industries, and other wastewater treatment environments. Siemens PACT technology has reportedly been installed at more than 100 locations.
Siemens’ PACT MBR is a powdered activated carbon-based wastewater treatment system that provides biological/physio-chemical/and ultrafiltration technology in a single, compact system, according to Meidensha. After extensive testing, Siemens approved Meidensha’s ceramic flat-sheet membrane for use in its PACT MBR system because of the membrane’s durability, abrasion resistance and long service life…

Debate continues over the merits of putting a price on carbon emissions — with many businesses opposing such a move. However, an increasing number of companies are adopting carbon pricing, according to a report released in September by CDP (formerly the Carbon Disclosure Project), London, a not-for-profit organization backed by institutional investors and others. The publication notes that carbon pricing already has spurred some firms to reallocate investments.
Called “Embedding a Carbon Price into Business Strategy,” the report summarizes the disclosures of companies around the world that responded to CDP’s 2016 climate-change and supply-chain information requests. A total of 1,249 firms revealed that they already price carbon…

With the aim to reduce toxic exposure, agency fast tracks the evaluation of five chemicals

The U.S. Environmental Protection Agency (EPA) is continuing its brisk pace to be on target with implementing the new requirements of the Toxic Substances Control Act (TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century…

Manufacturers must evaluate where to focus efforts to protect sensitive data.

Cybercriminals love chemical companies. In fact, IBM X-Force Research’s 2016 Cyber Security Intelligence Index cites chemical companies as one of the top targets for attackers, according to an article from Manufacturing Business Technology. The attacks are reportedly often financially-motivated and state-sponsored attempts to steal intellectual property and trade secrets.
So what can manufacturers do? The article’s author lays out a list of prevention methods beginning with a vulnerability management plan and ongoing vulnerability scans. According to the article, manufacturers should also promote company-wide security awareness, prepare an incident response plan, harden the security configurations of systems and servers and evaluate…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

Locate suppliers in the chemical, petrochemical and refining industries.

The year in review recalls some of the most important events of 2016, and the 2017 Supplier Sourcing Guide Directory is a look forward – a tool we hope helps you throughout the new year.
The 2017 Supplier Source Guide is an easy-to-use guide to help locate suppliers to the chemical, petrochemical and refining industries.
The guide is broken out into five primary categories:1. Asset Management2. Automation3. Environmental Protection4. Processing Equipment5. Safety/Security.
Each of these main categories includes several product sub-categories listed within them.
This easy-to-use directory lists suppliers in 43 categories of equipment, products, services and software. We also have a special section focusing on 72 engineering, construction…

If you use desiccant air dryers in your plant, you probably know they can consume a lot of energy dollars. Much of this money often is wasted. However, you likely can take a number of steps to reduce your desiccant dryer costs and improve the dryer operation, leading to better air quality. Here, we’ll look at five factors worth attention: specifications check, dryer control, desiccant protection, adjustments and maintenance.
First let’s consider operating costs, though. Compressed air is one of the most expensive utilities to use in doing anything in your plant. This is because of the poor “wire to work” conversion efficiency of the compression process. Only ≈10–15% of the energy put into a compressor actually converts to…

The U.S. Department of Energy announces nearly $25 million to enable innovative electrical motors used in manufacturing.

The U.S. Department of Energy announces nearly $25 million for 13 projects aimed at advancing energy-efficient electric motor technologies through applied research and development. The Office of Energy Efficiency and Renewable Energy’s (EERE) Next Generation Electric Machines projects will address the limitations of traditional materials and designs used in electric motor components by cost-effectively enhancing their efficiency, improving their performance and reducing weight. This effort will support approaches to improve the technology in industrial electric motors, which use approximately 70% of the electricity consumed by U.S. manufacturers and nearly a quarter of all electricity consumed nationally, according to EERE.
Improvements…

The new website is designed to be more visually appealing and user friendly.

Paratherm – Heat Transfer Fluids introduces a newly redesigned website. The new website is designed to be more visually appealing and user friendly, according to the company. The new Paratherm website reportedly performs many of the same duties as Paratherm employees in assisting hot oil system users and others interested in indirect heating technology.
The website is aimed at fluid customers, OEM design engineers, process managers, fluid specifiers and maintenance professionals. It provides technical details of Paratherm heat transfer fluid products, including product data, safety data and physical and thermal properties. The website also offers technical advice regarding hot-oil system safety, maintenance and reliability and detailed…

Water availability is a growing concern, prompting important initiatives by chemical companies, as our recent cover story “Keep Calm and Save Water,” underscores. Of course, the issue has much broader implications — and this has led to the…

Focusing on an implementation’s true consequences can lead to more cost-effective results

Undertaking an energy assessment can be a daunting task, but it doesn’t have to be if the energy expert can understand and follow an “impact analysis.” So, this column will cover this methodology and cite a few examples of how to undertake an impact analysis while doing energy assessments.
Published ASME standards for energy assessments provide a good starting point and offer guidelines for conducting these assessments. Nevertheless, our resources — budgets, human resources, and time — are always limited. Hence, there’s a strong need to undertake energy assessments from an impact-level perspective and increase the cost-effectiveness of these efforts. We are still talking about a systems approach; I’m not suggesting cutting…

April 2006 Process Puzzler: Fixing a Fouled Flue Gas System

Readers identify the cause of poor absorption in flue gas system in this month's process puzzler.

Our flue gas scrubbing system is showing signs of wear; see Figure 1. The overall pressure drop has increased about 20%, the acid concentration produced in the absorber is dropping, the magnetic flow meter measuring the acid shows a higher flow rate than expected, it is becoming difficult to control the acid concentration in the scrubber and the speed of the exhaust fan is tracking upward. Upstream of the venturi is a fluid bed coke reactor. What can be done to eliminate the problem(s) What do you think is the root cause?

Figure 1

Fouled absorber?

I would suspect that there is plugging or internal failure in the absorber column. The decrease in the acid concentration suggests that there is a loss in the contact area between the scrubber water and the flue gas. The loss of contact area is increasing the load on the VFD exhaust fan. It is also possible that some material from the fluidized reactor has migrated to the absorber tower. I would suggest completing a pressure survey of the entire system first to isolate the source of the increased DP. If it is the absorber column, you could try the following: increase the scrubber water flow rate (make-up) to the absorber increasing the mass transfer in the column. This is a good short-term solution. If this does not work, it may be necessary to enter the tower and inspect the packing and internals and repair, or replace, as necessary.

Brad Piggott, Production EngineerAir Liquide America, Freeport, Texas

Test the equipment to define problem

Assuming that the increased pressure drop and reduced acid concentration are related, the venturi may not be working properly, the packed bed unit may be plugged or absorber inlet gas flow may have increased. If additional information is not available, I suggest that the operator repair the acid pump and replace the venturi nozzles. I expect that the root cause of the problem is corrosion in the acid feed pump or venturi nozzle. A second solution is to replace the acid production control valve. Under this case, the root cause is a defective acid control valve that does not sufficiently restrict the product acid flow --- producing a low strength acid. There may be internal problems with the absorber. The root cause, in this case, is an increase in scrubbed gas (probably from a gas leak in the absorber or duct). Increasing the scrubbed gas increases absorber pressure drop, dilutes the acid in the vapor phase and thereby reduces efficiency. Additional information could be obtained by determining the source of the pressure drop.

I would look at the venturi since this might not require a plant shutdown. The first step would be to check the acid flow to the venturi. The venturi spray nozzles are the key to inducing gas flow and good contact efficiency. Assuming good level control in the acid tank and a steady acid production flow, the output pressure of the pump would be a good indication of the flow to the venturi (using the pump curve and baseline information on the venturi and pump). High output pressure indicates low flow. If the flow is low, then the piping or venturi spray nozzles may be plugged; the solid can be determined once the pipe is disassembled and inspected . Closing the acid control valve for a measurement can also confirm plugging. A reduced flow to the venturi lowers the pressure drop across the venturi (slightly) and reduces the venturis efficiency. Alternatively, a low output pressure indicates either the pump or the venturi needs repair. If temporarily blocking in the pump (after the output pressure) raises the pressure to design shutoff head, then the pump is good and the venturi spray nozzles are eroded and in need of repair. Also, inspecting the acid tank bottoms may be useful --- look for brick from the venturi lining. If the flow to the venturi is normal, the venturi throat may be plugged with solids carried over from the coke reactor. Typically, this occurs where the liquid and gas contact: the throat. Throat-plugging tends to separate the liquid flow from the gas flow --- this reduces gas-liquid contact. The efficiency of the absorber decreases and venturi pressure increases. A high pressure lance, near the throat, may be able to remove deposits from the venturi.

Pressure drop in the packed beds might occur in either the mist eliminator or the packed beds of column inlets. A pressure survey should determine where the increased pressure drop is occurring. Heavy washing of the mist eliminator or inlet piping might reduce the pressure drop. If the increased pressure drop is in the packed beds, plugging and channeling might reduce absorption efficiency and increase pressure drop. Heavy washing of the packed beds might reduce the plugging. Alternatively, dumping and washing or replacing the packing may be required.

Precipitate or carry-over?

With the limited information available, it is hard to be comprehensive. Lets start with some questions. Is coke from the upstream fluid bed reactor allowing small coke particles to collect in the absorber? On the next turn-around, carefully clean out the absorber, learning what is precipitates are in the interstices, if any, to cause the higher delta P. If the system is scrubbing SOx, then they must be getting precipitants. To reduce delta P, consider replacing the packing. Install a packing with a reduced pressure drop but be careful to consider performance and durability.

Tom Murphy, CEO, Puritrol, Inc., Centerville, Mass.

Inspect the equipment

Either the venturi or the absorber, or both, need to be inspected. What to look for? For the venturi, inspect the spray nozzles. If they are worn, the water leaving these nozzles therefore had become a jet, rather than a spray. The entire overall condition of the venturi needs to be checked. For the absorber, packing should be inspected for possible fouling, packing breakdown and other problems. If the packing is observed to be compromised, then replacement with new packing may be justified. The absorber mesh pad needs to be inspected for possible fouling.

Figure 2

Figure 3

James Eldridge, EngineerLantec Products, Norwood, Mass.

Collapsed packing or internal failure

It would appear your scrubber and absorber internals are falling apart. This would explain the lack of mass transfer (lower acid concentration, higher flow) and the increased pressure drop (packing is becoming compacted).With a compacted bed and increased pressure drop, the flow to the fan is restricted causing the motor to speed up (like putting your hand on the inlet hose to your home vacuum). I would suggest the internals to the scrubber be inspected and repairs made as are necessary.

Jim Darby, Process Design EngineerLANXESS Inc., Sarnia Ontario

Packing is plugged

Check the differential pressures across the column beds. If the exhaust fan is running at a higher speed, plugging of the packing may be the root cause. Flushing or cleaning or changing the internals would correct the problem. Another cause of poor concentration or scrubbing would be "channeling" of the liquid as is descends through the packed section. If one or more of the spray nozzles are clogged or even partially clogged, liquid will not be evenly distributed through the packing. Absorption efficiency falls off and you see the acid concentration fall off.

Inspect the flow meter

There may be more than one problem and thus there may be more than one root cause. My conclusion is that the mag meter should be tested or replaced and the packing should be inspected or replaced. Inspections may reveal what is fouling the meter and the packing. It helps if you know the reliability of each of the systems. An in-house history would be useful. A comparison between current performance and new performance, based on an operator logbook, could narrow the causes.

Dirk Lohry, President Nulex, Inc., Sioux City, Iowa

Failed venturi

Your puzzle generated a lot of discussions around the office. What follows is a summary of some of our discussions: 1) failure of the venturi, 2) fouling in the absorber packing, 3) and, a combination of the first two.

An increase in particulate loading, perhaps from a defective cyclone (upstream), could be overwhelming the venturi; this loading could plug the nozzles in the venturi throat and the throat itself. Plugging would also cause the flow through the magnetic flow meter to increase for a centrifugal pump; the flow to the venturi would decrease. The fan speed would increase, in response to the throttled flow at the venturi throat -- the flow of gas to the absorber would decrease and the acid produced would decrease. The absorber packing could be fouled causing poor contact between the gas and liquid. The operators would decrease the throughput of the gas as much as possible to increase the acid concentration. Unless the flow to the venturi was cut back substantially, the flow to the flow meter would increase.

Ravi Rangan, Engineer VI,USEPA, New Castle, DE

Redesign the process!

The process as presented does not allow sufficient time for the acid to concentrate in the absorber. I would suggest the following design changes: a venturi feeds a cyclone and a density meter measures the acid concentration. See the sketch. Add a hydro cyclone to allow most of liquid to return to acid tank with the partially scrubbed gas stream to go forward to the main scrubber. By putting the gas stream through these two devices it would minimize the solids going along with the gas stream to the absorber which in turn causes plugging and increasing pressure drop. The use of a level indicating controller in the Absorber tank tied to the flow control valve on the inlet water should allow for good scrubbing; the customer should check the efficiencies to ensure that this makeup rate will still make all environmental permits. A minimum make-up flow is for startup (to keep the packing cool). Using a level-indicating controller for the strong acid tank allows the proper transfer from the main scrubber. A density meter in the strong acid line, along with a flow control valve on the acid line, should produce required concentration. One may need a temperature compensator for the density meter depending on the density change with temperature. While proper design may help minimize plugging in the future the customer needs a planned shutdown to clean out his absorber to get their system back to functionality.

Click to enlarge Figure 4

Barry Bershad, Process EngineerClariant Corp., Coventry, England

JUNE'S PUZZLER

A TEMA class BEM heat exchanger is the ubiquitous choice throughout the company. It serves as cooler for contact condensers and as reboiler heaters in the distillation columns. The units are made of carbon steel and have fixed tubesheets; so they are cheap, costing only $60,000 each. The cooler was designed for R-22/glycol in a cascade system on the shellside; R-22 was changed to brine. Corrosion takes a toll: these cooler are inspected every 3 months, typically rebuilt every year, and are thrown away after 4 years. Rebuild costs are about $4,000-$12,000. The reboiler heater plugs frequently --- about every three months. A recent shutdown resulted in injuries, unrelated to the work, and a fine by OSHA. The nondestructive testing technician complains frequently that it is nearly impossible to properly inspect these units with a boroscope; doing so the last time, he found a broken shell baffle tracing a neat cut into a tube. We are now considering an alternative unit: clad-Hastelloy C276 tubeside with carbon steel shell and a floating head design to allow tube sheets to be pulled for inspection. The coolers run $180,000 each but are predicted to last at least 8 years given semi-annual inspections at a cost of $2,000. Assume the new exchangers need to be rebuilt every 4 years at $10,000. Assume downtime costs $10,000/hour in lost production. Unfortunately, piping modifications, estimated at about $40,000 per unit, will be required to allow the tubesheet to be pulled. Would you go with this unit or choose something else?

Send us your comments, suggestions or solutions for this question by May 5, 2006. Well include as many of them as possible in the June 2006 issue. Send visuals --- a sketch is fine. E-mail us at ProcessPuzzler@putman.net or mail to ProcessPuzzler, Chemical Processing, 555 W. Pierce Rd., Suite 301, Itasca, IL 60143. Fax: 630 467-1120. Please include your name, title, location and company affiliation in the response.

And, of course, if you have a process problem youd like to pose to our readers, send it along and well be pleased to consider it for publication.